Conventional, stock, and after-market suspension products such as air shocks and air springs are generally preset to a specific maximum weight accommodation level. This preset suspension does not always provide the best ride or handling for the riders. Additionally, motorcycles are known to have harsh rides that are not comfortable for many riders such as the elderly, overweight individuals, and women.
Current springs used in motorcycles can be progressive in that their lifespan and use deteriorate over time. For example, as the spring compresses, the spring weakens over time, making the ride less desirable for the riders.
Conventional air suspension systems often result in nonsmooth and uncomfortable rides, coupled with undesirable vehicle ride performance.
Various types of air suspension systems have been proposed over the years. U.S. Pat. No. 6,648,309 to Beck describes a piston rod with low/high pressure chambers. U.S. Pat. No. 6,374,966 to Lillbacka describes a piston rod that moves within the chamber and is surrounded by an outer chamber with sealing gaskets. An o-ring seals isolate compartment from environment outside of shock absorber; compressible fluid in inner chamber; coil spring provided about piston rod; air inlet, a fluid, i.e. air, pumped into elastomeric tube so that the inflated elastomeric tube acts as air spring to enhance shock absorbing ability of shock absorber.
U.S. Pat. No. 6,244,398 to Girvin describes a shock absorber with a shaft that extends into a reservoir housing which includes a hydraulic reservoir and gas chamber. The chamber seal includes an o-ring to separate the gas chamber from the hydraulic reservoir. There are springs on the shaft, a piston, and shim washers at the end of the piston, a reservoir cap, reservoir seal, and a bumper.
U.S. Pat. No. 5,833,036 to Gillespie describes an airbag in a reservoir of a cylinder, a piston assembly disposed within an inner cylinder and mounted to a piston rod. The piston rod comprising of piston assembly piston, check valve, a seal ring, seal ring carrier, bypass spring, spring abutment plate, and an end outer cylinder sealed plate with threaded mounting member.
U.S. Pat. No. 5,458,219 to Anderson describes a piston; reservoir containing gas cells. U.S. Pat. No. 5,172,794 to Ward describes a gas bag; piston assembly disposed within inner cylinder; piston rod that moves within piston assembly and extends into rebound chamber; outer cylinder with end cap; seal ring; ring; spring; and an end cap.
U.S. Pat. No. 4,664,234 to Wight; U.S. Pat. No. 4,566,565 to Wicke et al.; and U.S. Pat. No. 4,560,042 to Sell et al.; each describe self pressurized dampers. U.S. Pat. No. 3,024,875 to Stultz describes a shock absorber. U.S. Pat. No. 2,571,279 to Nils O. Mykestad describes a cylinder that defines a fluid reservoir containing a sack where air is introduced to a piston rod with sealing means and springs bear against it. And U.S. Pat. No. 2,324,058 to A. Boor et al. describes a hydraulic shock absorber structure.
U.S. Pat. No. 8,113,322 to Arnott, which has the same assignee as the subject invention, which is incorporated by reference in its' entirety, describes a motorcycle air suspension system and method that requires the use of two identical air suspension devices 1, FIG. 14 mounted side by side to provide adjustable air suspension for the rider.
FIG. 13 shows another prior art side cross-sectional view of a current shock that combines both air suspension through a spring and oil damping in one housing. Similar to Arnott '322, this combined air shock with damping would also be used in a pair arrangement as shown by FIG. 14 of the Arnott '322 patent.
FIG. 13 is a cross-sectional view of a prior art air suspension device with an internal damper 470. In the prior art assembly 470, includes an oil filled chamber 80 with an internal fixed damping piston 490 having a fixed damping piston shaft 500. Oil metering pass-through holes 510 are through the head of the piston 490. A ring attachment 520 secures the oil filled assembly to a bike frame or suspension member. Inside the air suspension device with internal damper 470 can be an airbag 530, top end 540, housing 550 and spring 560.
Combining both liquid damping with the air shock requires extra seals to keep fluid from leaking out of the housing and also contaminating the air suspension components in the same housing. As such, there can be reliability issues by combining both air suspension and the liquid damping effects in the same housing.
Additionally, the cost of using a pair of identical air suspension shocks with built in oil dampening adds extra expenses, where one or more of the combined units must be serviced and/or replaced.
The prior art discloses various types of air suspension systems and their respective components. However, none of the cited references overcomes the problems with the prior art described above. More particularly none of the prior art describes an easily adjustable system for use with motorcycles that allows the rider to have an adjustable ride based on the air suspension cylinders on those motorcycles.
Thus, the need exists for solutions to the above problems with the prior art.